I did some looking around and I found that 動作 is the behavior of machines and 行動 is the behavior of people, but that can't be it since on my textbook I find the following sentence:


Also saw some people saying that 行動 is the movement of people and 動作 is movement of the body, but I'm kinda confused about that.

Can someone explain the difference between these two words?

3 Answers 3


行動 is more like behavior or activity. It's a relatively complex movement of a lifeform that may take a long time and usually has a certain purpose. Examples of 行動 include "going shopping", "preparing and eating dinner", "playing baseball" and "attending a meeting". It's typically used for human activities, but you can also safely say アリの行動 or ロボットの行動 if it appears to be a purposeful sophisticated movement (or sequence of movements).

動作 refers to more primitive, mechanical movements. It can be involuntary. Examples of 動作 include "walking", "clapping hands", "hitting a ball with a bat" and "breathing". Operation of a machine or software is also called 動作.

  • コンピュータが「動作」するということに良く気づきましたね。(+1 upvote)いつかコンピュータが「行動」する時代が来るかも知れません。
    – user20624
    Jan 19, 2018 at 10:16

行動 can only be used for humans (and rarely for animals which display personality). 動作 can be used for machines, animals, humans, etc.

行動 refers to one's comportment and behavior (actions). 動作 refers to one's physical movements.

If someone stumbles a bit during the tea ceremony, despite using properly polite language, you would not say that their 'behavior'(行動) is bad as much as their 'movements' (動作).

  • 1
    – BJCUAI
    Jan 18, 2018 at 4:50

Let's take a look at the explanation by English native speakers about the difference. for just FYI.


行動 : the movement of someone if it be unconscious or intentional.


Physical movement of it and the effect, movement.

地震の際には、落ち着いて適切な行動をとって身体の安全を確保しましょう。 不注意な行動が大きな危険を招きます。

Place yourself to security area, with with due composure in a case of the earthquake. Your careless action could put you in danger.

ダンサーが舞台に登場して、野生の猿のような不思議な動作をしてみせた。 彼は店員としてのトレーニングが未熟で、まだ店頭での動作がぎこちない。

The dancer acted with strange movement of a wild ape while he is on the stage. He is still inexperienced in training, so his movement on the stage is awkward.

So that, whereas 行動 has broader sense of action, 動作 is more centered on the very motion/movement by someone/something.

  • 2
    – user20624
    Jan 18, 2018 at 6:57
  • 2
    – user20624
    Jan 18, 2018 at 7:00
  • >まだ店頭での動作がぎこちない。こちらは「人」ですので、「動作」でも問題はないですが、「動作」だと何となく「動物」っぽい感じもしますので、「振る舞い」あるいは「所作」という言葉の方がふさわしいような気もします。
    – user20624
    Jan 18, 2018 at 7:04
  • ダンサーの例文と、ぎごちない動作の店員の例文とは全く別のような感じがしますので、行を改めた方が良いように思います。
    – user20624
    Jan 18, 2018 at 7:07
  • Sorry for being late. Yes, mackygoo san is correct. May be I have tried to answer from not a good site. For example, we can say ”あの動物の行動は・・・”etc, not limited to human beings. Thank you.
    – user7644
    Jan 19, 2018 at 5:27

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